Not so much a post of my WIP (even though it is one) but more of a ask for help regarding a flicker issue. The backgrounds occasionally flash black, and I cannot figure out why. It seems to only happen in the NW.js preview but not in the HTML web version?

I am really stumped why this flicker happens. I have the latest video driver from nVidia, etc.

Thanks,

Is it related to the 1000px wide/tall tiling backgrounds overlapping with transparency using Sine behavior (sawtooth)? I tried to make scrolling backgrounds based on @jerementor idea from his Udemy course (that checkerboard diagonal scrolling effect) but maybe I screwed it up. I've got a 256x256 tiling background which I offset -128, -128 and set the amplitude to 128.